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dc17e9e9 RS |
1 | /* Specialized bits of code needed to support construction and |
2 | destruction of file-scope objects in C++ code. | |
31cf0144 | 3 | Copyright (C) 1991, 1994-1999 Free Software Foundation, Inc. |
d0f8fcea | 4 | Contributed by Ron Guilmette (rfg@monkeys.com). |
dc17e9e9 RS |
5 | |
6 | This file is part of GNU CC. | |
7 | ||
8 | GNU CC is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2, or (at your option) | |
11 | any later version. | |
12 | ||
13 | GNU CC is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with GNU CC; see the file COPYING. If not, write to | |
940d9d63 RK |
20 | the Free Software Foundation, 59 Temple Place - Suite 330, |
21 | Boston, MA 02111-1307, USA. */ | |
dc17e9e9 RS |
22 | |
23 | /* As a special exception, if you link this library with files | |
24 | compiled with GCC to produce an executable, this does not cause | |
25 | the resulting executable to be covered by the GNU General Public License. | |
26 | This exception does not however invalidate any other reasons why | |
27 | the executable file might be covered by the GNU General Public License. */ | |
28 | ||
29 | /* This file is a bit like libgcc1.c/libgcc2.c in that it is compiled | |
30 | multiple times and yields multiple .o files. | |
31 | ||
32 | This file is useful on target machines where the object file format | |
33 | supports multiple "user-defined" sections (e.g. COFF, ELF, ROSE). On | |
34 | such systems, this file allows us to avoid running collect (or any | |
35 | other such slow and painful kludge). Additionally, if the target | |
36 | system supports a .init section, this file allows us to support the | |
37 | linking of C++ code with a non-C++ main program. | |
38 | ||
39 | Note that if INIT_SECTION_ASM_OP is defined in the tm.h file, then | |
40 | this file *will* make use of the .init section. If that symbol is | |
41 | not defined however, then the .init section will not be used. | |
42 | ||
37ce5b86 CH |
43 | Currently, only ELF and COFF are supported. It is likely however that |
44 | ROSE could also be supported, if someone was willing to do the work to | |
45 | make whatever (small?) adaptations are needed. (Some work may be | |
46 | needed on the ROSE assembler and linker also.) | |
dc17e9e9 RS |
47 | |
48 | This file must be compiled with gcc. */ | |
49 | ||
50 | /* It is incorrect to include config.h here, because this file is being | |
51 | compiled for the target, and hence definitions concerning only the host | |
52 | do not apply. */ | |
53 | ||
54 | #include "tm.h" | |
0021b564 | 55 | #include "defaults.h" |
956d6950 JL |
56 | #include <stddef.h> |
57 | #include "frame.h" | |
dc17e9e9 | 58 | |
8f08ea1e L |
59 | /* We do not want to add the weak attribute to the declarations of these |
60 | routines in frame.h because that will cause the definition of these | |
61 | symbols to be weak as well. | |
62 | ||
63 | This exposes a core issue, how to handle creating weak references vs | |
64 | how to create weak definitions. Either we have to have the definition | |
65 | of TARGET_WEAK_ATTRIBUTE be conditional in the shared header files or | |
66 | have a second declaration if we want a function's references to be weak, | |
67 | but not its definition. | |
68 | ||
69 | Making TARGET_WEAK_ATTRIBUTE conditional seems like a good solution until | |
70 | one thinks about scaling to larger problems -- ie, the condition under | |
71 | which TARGET_WEAK_ATTRIBUTE is active will eventually get far too | |
72 | complicated. | |
73 | ||
74 | So, we take an approach similar to #pragma weak -- we have a second | |
75 | declaration for functions that we want to have weak references. | |
76 | ||
77 | Neither way is particularly good. */ | |
78 | ||
79 | /* References to __register_frame_info and __deregister_frame_info should | |
80 | be weak in this file if at all possible. */ | |
81 | extern void __register_frame_info (void *, struct object *) | |
82 | TARGET_ATTRIBUTE_WEAK; | |
83 | ||
84 | extern void *__deregister_frame_info (void *) | |
85 | TARGET_ATTRIBUTE_WEAK; | |
86 | ||
750930c1 MN |
87 | #ifndef OBJECT_FORMAT_MACHO |
88 | ||
68d69835 JM |
89 | /* Provide default definitions for the pseudo-ops used to switch to the |
90 | .ctors and .dtors sections. | |
91 | ||
92 | Note that we want to give these sections the SHF_WRITE attribute | |
93 | because these sections will actually contain data (i.e. tables of | |
94 | addresses of functions in the current root executable or shared library | |
95 | file) and, in the case of a shared library, the relocatable addresses | |
96 | will have to be properly resolved/relocated (and then written into) by | |
97 | the dynamic linker when it actually attaches the given shared library | |
98 | to the executing process. (Note that on SVR4, you may wish to use the | |
99 | `-z text' option to the ELF linker, when building a shared library, as | |
100 | an additional check that you are doing everything right. But if you do | |
101 | use the `-z text' option when building a shared library, you will get | |
102 | errors unless the .ctors and .dtors sections are marked as writable | |
103 | via the SHF_WRITE attribute.) */ | |
104 | ||
dc17e9e9 | 105 | #ifndef CTORS_SECTION_ASM_OP |
68d69835 | 106 | #define CTORS_SECTION_ASM_OP ".section\t.ctors,\"aw\"" |
dc17e9e9 RS |
107 | #endif |
108 | #ifndef DTORS_SECTION_ASM_OP | |
68d69835 | 109 | #define DTORS_SECTION_ASM_OP ".section\t.dtors,\"aw\"" |
dc17e9e9 RS |
110 | #endif |
111 | ||
68d69835 JM |
112 | #ifdef OBJECT_FORMAT_ELF |
113 | ||
114 | /* Declare a pointer to void function type. */ | |
115 | typedef void (*func_ptr) (void); | |
116 | #define STATIC static | |
117 | ||
118 | #else /* OBJECT_FORMAT_ELF */ | |
119 | ||
dc17e9e9 RS |
120 | #include "gbl-ctors.h" |
121 | ||
122 | #ifndef ON_EXIT | |
123 | #define ON_EXIT(a, b) | |
124 | #endif | |
68d69835 JM |
125 | #define STATIC |
126 | ||
127 | #endif /* OBJECT_FORMAT_ELF */ | |
dc17e9e9 RS |
128 | |
129 | #ifdef CRT_BEGIN | |
130 | ||
131 | #ifdef INIT_SECTION_ASM_OP | |
132 | ||
68d69835 JM |
133 | #ifdef OBJECT_FORMAT_ELF |
134 | ||
135 | /* Run all the global destructors on exit from the program. */ | |
136 | ||
137 | /* Some systems place the number of pointers in the first word of the | |
138 | table. On SVR4 however, that word is -1. In all cases, the table is | |
139 | null-terminated. On SVR4, we start from the beginning of the list and | |
140 | invoke each per-compilation-unit destructor routine in order | |
141 | until we find that null. | |
142 | ||
143 | Note that this function MUST be static. There will be one of these | |
144 | functions in each root executable and one in each shared library, but | |
145 | although they all have the same code, each one is unique in that it | |
146 | refers to one particular associated `__DTOR_LIST__' which belongs to the | |
b40b9d93 MS |
147 | same particular root executable or shared library file. |
148 | ||
149 | On some systems, this routine is run more than once from the .fini, | |
150 | when exit is called recursively, so we arrange to remember where in | |
151 | the list we left off processing, and we resume at that point, | |
152 | should we be re-invoked. */ | |
68d69835 | 153 | |
0021b564 | 154 | static char __EH_FRAME_BEGIN__[]; |
68d69835 JM |
155 | static func_ptr __DTOR_LIST__[]; |
156 | static void | |
3cc22c31 | 157 | __do_global_dtors_aux (void) |
68d69835 | 158 | { |
b40b9d93 | 159 | static func_ptr *p = __DTOR_LIST__ + 1; |
5041a61c JL |
160 | static int completed = 0; |
161 | ||
162 | if (completed) | |
163 | return; | |
164 | ||
b40b9d93 MS |
165 | while (*p) |
166 | { | |
167 | p++; | |
168 | (*(p-1)) (); | |
169 | } | |
0021b564 JM |
170 | |
171 | #ifdef EH_FRAME_SECTION_ASM_OP | |
8f08ea1e L |
172 | if (__deregister_frame_info) |
173 | __deregister_frame_info (__EH_FRAME_BEGIN__); | |
0021b564 | 174 | #endif |
5041a61c | 175 | completed = 1; |
68d69835 JM |
176 | } |
177 | ||
5041a61c | 178 | |
68d69835 | 179 | /* Stick a call to __do_global_dtors_aux into the .fini section. */ |
0f41302f | 180 | |
50b2596f | 181 | static void __attribute__ ((__unused__)) |
3cc22c31 | 182 | fini_dummy (void) |
68d69835 JM |
183 | { |
184 | asm (FINI_SECTION_ASM_OP); | |
185 | __do_global_dtors_aux (); | |
186 | #ifdef FORCE_FINI_SECTION_ALIGN | |
187 | FORCE_FINI_SECTION_ALIGN; | |
188 | #endif | |
189 | asm (TEXT_SECTION_ASM_OP); | |
190 | } | |
191 | ||
0021b564 | 192 | #ifdef EH_FRAME_SECTION_ASM_OP |
6d8ccdbb JL |
193 | /* Stick a call to __register_frame_info into the .init section. For some |
194 | reason calls with no arguments work more reliably in .init, so stick the | |
195 | call in another function. */ | |
0021b564 JM |
196 | |
197 | static void | |
3cc22c31 | 198 | frame_dummy (void) |
0021b564 | 199 | { |
956d6950 | 200 | static struct object object; |
8f08ea1e L |
201 | if (__register_frame_info) |
202 | __register_frame_info (__EH_FRAME_BEGIN__, &object); | |
0021b564 JM |
203 | } |
204 | ||
50b2596f | 205 | static void __attribute__ ((__unused__)) |
3cc22c31 | 206 | init_dummy (void) |
0021b564 JM |
207 | { |
208 | asm (INIT_SECTION_ASM_OP); | |
209 | frame_dummy (); | |
210 | #ifdef FORCE_INIT_SECTION_ALIGN | |
211 | FORCE_INIT_SECTION_ALIGN; | |
212 | #endif | |
213 | asm (TEXT_SECTION_ASM_OP); | |
214 | } | |
215 | #endif /* EH_FRAME_SECTION_ASM_OP */ | |
216 | ||
68d69835 JM |
217 | #else /* OBJECT_FORMAT_ELF */ |
218 | ||
b335c2cc | 219 | /* The function __do_global_ctors_aux is compiled twice (once in crtbegin.o |
b71a4aa9 | 220 | and once in crtend.o). It must be declared static to avoid a link |
b335c2cc TW |
221 | error. Here, we define __do_global_ctors as an externally callable |
222 | function. It is externally callable so that __main can invoke it when | |
223 | INVOKE__main is defined. This has the additional effect of forcing cc1 | |
224 | to switch to the .text section. */ | |
0f41302f | 225 | |
93c3d169 | 226 | static void __do_global_ctors_aux (); |
3cc22c31 JL |
227 | void |
228 | __do_global_ctors (void) | |
329d2160 RS |
229 | { |
230 | #ifdef INVOKE__main /* If __main won't actually call __do_global_ctors | |
231 | then it doesn't matter what's inside the function. | |
232 | The inside of __do_global_ctors_aux is called | |
233 | automatically in that case. | |
234 | And the Alliant fx2800 linker crashes | |
235 | on this reference. So prevent the crash. */ | |
236 | __do_global_ctors_aux (); | |
237 | #endif | |
238 | } | |
dc17e9e9 RS |
239 | |
240 | asm (INIT_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */ | |
241 | ||
5378943d RK |
242 | /* On some svr4 systems, the initial .init section preamble code provided in |
243 | crti.o may do something, such as bump the stack, which we have to | |
244 | undo before we reach the function prologue code for __do_global_ctors | |
245 | (directly below). For such systems, define the macro INIT_SECTION_PREAMBLE | |
0f41302f | 246 | to expand into the code needed to undo the actions of the crti.o file. */ |
5378943d RK |
247 | |
248 | #ifdef INIT_SECTION_PREAMBLE | |
249 | INIT_SECTION_PREAMBLE; | |
250 | #endif | |
251 | ||
dc17e9e9 RS |
252 | /* A routine to invoke all of the global constructors upon entry to the |
253 | program. We put this into the .init section (for systems that have | |
254 | such a thing) so that we can properly perform the construction of | |
255 | file-scope static-storage C++ objects within shared libraries. */ | |
256 | ||
257 | static void | |
3cc22c31 | 258 | __do_global_ctors_aux (void) /* prologue goes in .init section */ |
dc17e9e9 | 259 | { |
5868ca20 JW |
260 | #ifdef FORCE_INIT_SECTION_ALIGN |
261 | FORCE_INIT_SECTION_ALIGN; /* Explicit align before switch to .text */ | |
262 | #endif | |
dc17e9e9 RS |
263 | asm (TEXT_SECTION_ASM_OP); /* don't put epilogue and body in .init */ |
264 | DO_GLOBAL_CTORS_BODY; | |
265 | ON_EXIT (__do_global_dtors, 0); | |
266 | } | |
267 | ||
68d69835 | 268 | #endif /* OBJECT_FORMAT_ELF */ |
fe1fd353 JM |
269 | |
270 | #else /* defined(INIT_SECTION_ASM_OP) */ | |
271 | ||
9593ce03 | 272 | #ifdef HAS_INIT_SECTION |
fe1fd353 JM |
273 | /* This case is used by the Irix 6 port, which supports named sections but |
274 | not an SVR4-style .fini section. __do_global_dtors can be non-static | |
0021b564 JM |
275 | in this case because we protect it with -hidden_symbol. */ |
276 | ||
277 | static char __EH_FRAME_BEGIN__[]; | |
fe1fd353 JM |
278 | static func_ptr __DTOR_LIST__[]; |
279 | void | |
3cc22c31 | 280 | __do_global_dtors (void) |
fe1fd353 JM |
281 | { |
282 | func_ptr *p; | |
283 | for (p = __DTOR_LIST__ + 1; *p; p++) | |
284 | (*p) (); | |
0021b564 JM |
285 | |
286 | #ifdef EH_FRAME_SECTION_ASM_OP | |
8f08ea1e L |
287 | if (__deregister_frame_info) |
288 | __deregister_frame_info (__EH_FRAME_BEGIN__); | |
0021b564 | 289 | #endif |
fe1fd353 | 290 | } |
35a42f5f JW |
291 | |
292 | #ifdef EH_FRAME_SECTION_ASM_OP | |
293 | /* Define a function here to call __register_frame. crtend.o is linked in | |
294 | after libgcc.a, and hence can't call libgcc.a functions directly. That | |
295 | can lead to unresolved function references. */ | |
296 | void | |
3cc22c31 | 297 | __frame_dummy (void) |
35a42f5f JW |
298 | { |
299 | static struct object object; | |
8f08ea1e L |
300 | if (__register_frame_info) |
301 | __register_frame_info (__EH_FRAME_BEGIN__, &object); | |
35a42f5f JW |
302 | } |
303 | #endif | |
9593ce03 | 304 | #endif |
fe1fd353 | 305 | |
dc17e9e9 RS |
306 | #endif /* defined(INIT_SECTION_ASM_OP) */ |
307 | ||
308 | /* Force cc1 to switch to .data section. */ | |
d6f4ec51 | 309 | static func_ptr force_to_data[0] __attribute__ ((__unused__)) = { }; |
dc17e9e9 | 310 | |
68d69835 JM |
311 | /* NOTE: In order to be able to support SVR4 shared libraries, we arrange |
312 | to have one set of symbols { __CTOR_LIST__, __DTOR_LIST__, __CTOR_END__, | |
313 | __DTOR_END__ } per root executable and also one set of these symbols | |
314 | per shared library. So in any given whole process image, we may have | |
315 | multiple definitions of each of these symbols. In order to prevent | |
316 | these definitions from conflicting with one another, and in order to | |
317 | ensure that the proper lists are used for the initialization/finalization | |
318 | of each individual shared library (respectively), we give these symbols | |
319 | only internal (i.e. `static') linkage, and we also make it a point to | |
320 | refer to only the __CTOR_END__ symbol in crtend.o and the __DTOR_LIST__ | |
321 | symbol in crtbegin.o, where they are defined. */ | |
322 | ||
dc17e9e9 RS |
323 | /* The -1 is a flag to __do_global_[cd]tors |
324 | indicating that this table does not start with a count of elements. */ | |
b335c2cc TW |
325 | #ifdef CTOR_LIST_BEGIN |
326 | CTOR_LIST_BEGIN; | |
327 | #else | |
dc17e9e9 | 328 | asm (CTORS_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */ |
d6f4ec51 KG |
329 | STATIC func_ptr __CTOR_LIST__[1] __attribute__ ((__unused__)) |
330 | = { (func_ptr) (-1) }; | |
b335c2cc | 331 | #endif |
dc17e9e9 | 332 | |
b335c2cc TW |
333 | #ifdef DTOR_LIST_BEGIN |
334 | DTOR_LIST_BEGIN; | |
335 | #else | |
dc17e9e9 | 336 | asm (DTORS_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */ |
68d69835 | 337 | STATIC func_ptr __DTOR_LIST__[1] = { (func_ptr) (-1) }; |
b335c2cc | 338 | #endif |
dc17e9e9 | 339 | |
0021b564 JM |
340 | #ifdef EH_FRAME_SECTION_ASM_OP |
341 | /* Stick a label at the beginning of the frame unwind info so we can register | |
342 | and deregister it with the exception handling library code. */ | |
343 | ||
344 | asm (EH_FRAME_SECTION_ASM_OP); | |
345 | #ifdef INIT_SECTION_ASM_OP | |
346 | STATIC | |
347 | #endif | |
348 | char __EH_FRAME_BEGIN__[] = { }; | |
349 | #endif /* EH_FRAME_SECTION_ASM_OP */ | |
350 | ||
dc17e9e9 RS |
351 | #endif /* defined(CRT_BEGIN) */ |
352 | ||
353 | #ifdef CRT_END | |
354 | ||
355 | #ifdef INIT_SECTION_ASM_OP | |
356 | ||
68d69835 | 357 | #ifdef OBJECT_FORMAT_ELF |
dc17e9e9 | 358 | |
68d69835 JM |
359 | static func_ptr __CTOR_END__[]; |
360 | static void | |
3cc22c31 | 361 | __do_global_ctors_aux (void) |
68d69835 JM |
362 | { |
363 | func_ptr *p; | |
364 | for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--) | |
365 | (*p) (); | |
366 | } | |
367 | ||
368 | /* Stick a call to __do_global_ctors_aux into the .init section. */ | |
0f41302f | 369 | |
50b2596f | 370 | static void __attribute__ ((__unused__)) |
3cc22c31 | 371 | init_dummy (void) |
68d69835 JM |
372 | { |
373 | asm (INIT_SECTION_ASM_OP); | |
374 | __do_global_ctors_aux (); | |
375 | #ifdef FORCE_INIT_SECTION_ALIGN | |
376 | FORCE_INIT_SECTION_ALIGN; | |
377 | #endif | |
378 | asm (TEXT_SECTION_ASM_OP); | |
bced43dd | 379 | |
956d6950 | 380 | /* This is a kludge. The i386 GNU/Linux dynamic linker needs ___brk_addr, |
d0f8fcea RK |
381 | __environ and atexit (). We have to make sure they are in the .dynsym |
382 | section. We accomplish it by making a dummy call here. This | |
0f41302f | 383 | code is never reached. */ |
bced43dd | 384 | |
d0f8fcea | 385 | #if defined(__linux__) && defined(__PIC__) && defined(__i386__) |
bced43dd RK |
386 | { |
387 | extern void *___brk_addr; | |
388 | extern char **__environ; | |
389 | ||
390 | ___brk_addr = __environ; | |
391 | atexit (); | |
392 | } | |
393 | #endif | |
68d69835 JM |
394 | } |
395 | ||
396 | #else /* OBJECT_FORMAT_ELF */ | |
397 | ||
398 | /* Stick the real initialization code, followed by a normal sort of | |
399 | function epilogue at the very end of the .init section for this | |
400 | entire root executable file or for this entire shared library file. | |
401 | ||
402 | Note that we use some tricks here to get *just* the body and just | |
403 | a function epilogue (but no function prologue) into the .init | |
9faa82d8 | 404 | section of the crtend.o file. Specifically, we switch to the .text |
68d69835 JM |
405 | section, start to define a function, and then we switch to the .init |
406 | section just before the body code. | |
407 | ||
408 | Earlier on, we put the corresponding function prologue into the .init | |
409 | section of the crtbegin.o file (which will be linked in first). | |
410 | ||
411 | Note that we want to invoke all constructors for C++ file-scope static- | |
412 | storage objects AFTER any other possible initialization actions which | |
413 | may be performed by the code in the .init section contributions made by | |
414 | other libraries, etc. That's because those other initializations may | |
415 | include setup operations for very primitive things (e.g. initializing | |
416 | the state of the floating-point coprocessor, etc.) which should be done | |
0f41302f | 417 | before we start to execute any of the user's code. */ |
dc17e9e9 RS |
418 | |
419 | static void | |
3cc22c31 | 420 | __do_global_ctors_aux (void) /* prologue goes in .text section */ |
dc17e9e9 RS |
421 | { |
422 | asm (INIT_SECTION_ASM_OP); | |
423 | DO_GLOBAL_CTORS_BODY; | |
424 | ON_EXIT (__do_global_dtors, 0); | |
e5e809f4 JL |
425 | } /* epilogue and body go in .init section */ |
426 | ||
c85f7c16 | 427 | #ifdef FORCE_INIT_SECTION_ALIGN |
e5e809f4 | 428 | FORCE_INIT_SECTION_ALIGN; |
c85f7c16 | 429 | #endif |
e5e809f4 JL |
430 | |
431 | asm (TEXT_SECTION_ASM_OP); | |
dc17e9e9 | 432 | |
68d69835 JM |
433 | #endif /* OBJECT_FORMAT_ELF */ |
434 | ||
fe1fd353 JM |
435 | #else /* defined(INIT_SECTION_ASM_OP) */ |
436 | ||
9593ce03 | 437 | #ifdef HAS_INIT_SECTION |
fe1fd353 JM |
438 | /* This case is used by the Irix 6 port, which supports named sections but |
439 | not an SVR4-style .init section. __do_global_ctors can be non-static | |
0021b564 | 440 | in this case because we protect it with -hidden_symbol. */ |
fe1fd353 | 441 | static func_ptr __CTOR_END__[]; |
50b2596f KG |
442 | #ifdef EH_FRAME_SECTION_ASM_OP |
443 | extern void __frame_dummy (void); | |
444 | #endif | |
fe1fd353 | 445 | void |
3cc22c31 | 446 | __do_global_ctors (void) |
fe1fd353 JM |
447 | { |
448 | func_ptr *p; | |
0021b564 | 449 | #ifdef EH_FRAME_SECTION_ASM_OP |
35a42f5f | 450 | __frame_dummy (); |
0021b564 | 451 | #endif |
fe1fd353 JM |
452 | for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--) |
453 | (*p) (); | |
454 | } | |
9593ce03 | 455 | #endif |
fe1fd353 | 456 | |
dc17e9e9 RS |
457 | #endif /* defined(INIT_SECTION_ASM_OP) */ |
458 | ||
459 | /* Force cc1 to switch to .data section. */ | |
d6f4ec51 | 460 | static func_ptr force_to_data[0] __attribute__ ((__unused__)) = { }; |
dc17e9e9 | 461 | |
68d69835 JM |
462 | /* Put a word containing zero at the end of each of our two lists of function |
463 | addresses. Note that the words defined here go into the .ctors and .dtors | |
464 | sections of the crtend.o file, and since that file is always linked in | |
465 | last, these words naturally end up at the very ends of the two lists | |
466 | contained in these two sections. */ | |
467 | ||
b335c2cc TW |
468 | #ifdef CTOR_LIST_END |
469 | CTOR_LIST_END; | |
470 | #else | |
dc17e9e9 | 471 | asm (CTORS_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */ |
68d69835 | 472 | STATIC func_ptr __CTOR_END__[1] = { (func_ptr) 0 }; |
b335c2cc | 473 | #endif |
dc17e9e9 | 474 | |
b335c2cc TW |
475 | #ifdef DTOR_LIST_END |
476 | DTOR_LIST_END; | |
477 | #else | |
dc17e9e9 | 478 | asm (DTORS_SECTION_ASM_OP); /* cc1 doesn't know that we are switching! */ |
d6f4ec51 KG |
479 | STATIC func_ptr __DTOR_END__[1] __attribute__ ((__unused__)) |
480 | = { (func_ptr) 0 }; | |
b335c2cc | 481 | #endif |
dc17e9e9 | 482 | |
0021b564 JM |
483 | #ifdef EH_FRAME_SECTION_ASM_OP |
484 | /* Terminate the frame unwind info section with a 4byte 0 as a sentinel; | |
485 | this would be the 'length' field in a real FDE. */ | |
486 | ||
487 | typedef unsigned int ui32 __attribute__ ((mode (SI))); | |
488 | asm (EH_FRAME_SECTION_ASM_OP); | |
d6f4ec51 | 489 | STATIC ui32 __FRAME_END__[] __attribute__ ((__unused__)) = { 0 }; |
0021b564 JM |
490 | #endif /* EH_FRAME_SECTION */ |
491 | ||
dc17e9e9 | 492 | #endif /* defined(CRT_END) */ |
750930c1 MN |
493 | |
494 | #else /* OBJECT_FORMAT_MACHO */ | |
495 | ||
496 | /* For Mach-O format executables, we assume that the system's runtime is | |
497 | smart enough to handle constructors and destructors, but doesn't have | |
498 | an init section (if it can't even handle constructors/destructors | |
499 | you should be using INVOKE__main, not crtstuff). All we need to do | |
500 | is install/deinstall the frame information for exceptions. We do this | |
501 | by putting a constructor in crtbegin.o and a destructor in crtend.o. | |
502 | ||
503 | crtend.o also puts in the terminating zero in the frame information | |
504 | segment. */ | |
505 | ||
506 | /* The crtstuff for other object formats use the symbol __EH_FRAME_BEGIN__ | |
507 | to figure out the start of the exception frame, but here we use | |
508 | getsectbynamefromheader to find this value. Either method would work, | |
509 | but this method avoids creating any global symbols, which seems | |
510 | cleaner. */ | |
511 | ||
512 | #include <mach-o/ldsyms.h> | |
513 | extern const struct section * | |
514 | getsectbynamefromheader (const struct mach_header *, | |
515 | const char *, const char *); | |
516 | ||
517 | #ifdef CRT_BEGIN | |
518 | ||
519 | static void __reg_frame_ctor () __attribute__ ((constructor)); | |
520 | ||
521 | static void | |
3cc22c31 | 522 | __reg_frame_ctor (void) |
750930c1 MN |
523 | { |
524 | static struct object object; | |
525 | const struct section *eh_frame; | |
526 | ||
527 | eh_frame = getsectbynamefromheader (&_mh_execute_header, | |
528 | "__TEXT", "__eh_frame"); | |
529 | __register_frame_info ((void *) eh_frame->addr, &object); | |
530 | } | |
531 | ||
532 | #endif /* CRT_BEGIN */ | |
533 | ||
534 | #ifdef CRT_END | |
535 | ||
536 | static void __dereg_frame_dtor () __attribute__ ((destructor)); | |
537 | ||
538 | static | |
3cc22c31 JL |
539 | void |
540 | __dereg_frame_dtor (void) | |
750930c1 MN |
541 | { |
542 | const struct section *eh_frame; | |
543 | ||
544 | eh_frame = getsectbynamefromheader (&_mh_execute_header, | |
545 | "__TEXT", "__eh_frame"); | |
546 | __deregister_frame_info ((void *) eh_frame->addr); | |
547 | } | |
548 | ||
549 | /* Terminate the frame section with a final zero. */ | |
550 | ||
551 | /* Force cc1 to switch to .data section. */ | |
552 | static void * force_to_data[0] __attribute__ ((__unused__)) = { }; | |
553 | ||
554 | typedef unsigned int ui32 __attribute__ ((mode (SI))); | |
555 | asm (EH_FRAME_SECTION_ASM_OP); | |
556 | static ui32 __FRAME_END__[] __attribute__ ((__unused__)) = { 0 }; | |
557 | ||
558 | #endif /* CRT_END */ | |
559 | ||
560 | #endif /* OBJECT_FORMAT_MACHO */ | |
561 |